Advanced Recreational Cavern/Cave Diving?

[Gombessa]

Color me stupid but how is a "vest BC bladder" different from a back inflate one?

I dunno Peter, the several "standard" vest BCs I've tried do have air bladders that wrap against the ribs, definitely NOT a backinflate design like the Knighthawk. In fact, I disliked the feeling and effect (needing to squeeze down with my elbows to equalize the air cells that I took to backinflate immediately.

As to whether the actual position being argued is "is this superior" to back inflate or "is this merely sufficient"...

 

[Bubbletrubble]

Based on the location of the bladder in a standard jacket-style BCD (with bladder hugging the ribs), I can see how that style of BCD (vs. a BP/W setup) might afford greater axial stability as the diver swims along on one side or the other in the water column. I'm not sure how this would be helpful in traveling through lava tube or cave restrictions, though.

 

[MauiScubaSteve]

Is it possible that a Vest BC is the best BC for a dive like this?

Please understand I am not advocating that any diver other than my BDB beanniebrew and myself do any dive similar to this one; YOU MOST CERTAINLY MIGHT DIE!

The entire dive, not all of it overhead, can be viewed at the following link;

Cave Dive - halemano's Photos- powered by SmugMug

I am not sure but it seems some of you may only be reading the title of the thread and then only looking at the pictures posted in this thread.

Even though I do not consider BC's (vest, back inflate or bp/w) to be survival gear, and even though I do not spend a lot of money on my BC's, I am still loath to put them in situations where they might be ruined.

Considering the triangular shape of some restrictions, where the tank is bumping/scraping in the top of the triangle, I think a wing (or even BI) is at significant risk of damage, compared to vest's. I do not do tight squeezes like this in my Balance.

This "advanced recreational penetration" is typically a small portion of the dive, not the sole purpose of the dive. On the dive featured at the link, the overhead portion is 20-25 minutes out of a 90 minute dive; often the overhead is even less time duration.

I know of a number of similar tight squeezes where to get through the tank is bumping/scraping on the roof. We are going very, very slowly so when a dangly gets snagged it is just a little back and forth wiggling to get it loose. If I were wearing my BI I would not go through a squeeze like the one in the posted pic's. It seems to me that I would feel the same about a wing if I used one.

The controversial aspects of my pictures seem to have given many an opt out from addressing the intent of the main Q; whether or not a vest BC might be the best BC for some dives.

 

[beanniebrew]

Why so in your face?

 

[Paladin]

Personally, I don't think of a BC as survival gear. For me, they are a convenience. If I were to try a swim through like those in the pics, my answer would be to leave the BC on the boat for that dive. Just a vintage style diver's $.02.

 

[TSandM]

One of the things that people seem to be missing in this discussion is that the wing is never inflated until it's taut. Properly weighted, one really doesn't have much gas in a wing. If the top of the wing comes into contact with the roof of the cave, it simply gives, and the air moves downward. If one were using such an oversized wing (as some of the 90+ pound ones might be) as to allow the bladder to fold over the top of the tank and get trapped between the roof and the metal, then you might damage the wing. If there are protrusions of rock that can catch the fabric, you might damage the fabric. But you'd have to be caught on something and really force yourself through it, with the wing hooked, to damage the inner bladder.

I've gone through quite a few restrictions that were tight enough that there was no way you could get through them without contacting the ceiling. I have no damage and no evidence of wear on my wing.

 

[RJP]

In my opinion there are tight squeezes where a wing would be more at risk of damage than a vest; the first two pic's posted above are of one of those tight squeezes.

1.) With the proper gear/configuration that's not a problem
2.) Even if that WAS a problem, it would be the LEAST of the problems

 

[RJP]

Here is a pic of Saspotato with a single tank (again plagiarized from her SB photo gallery), and look at the pic from HowardE again which seems to be a single tank;

​

That wing seems to be a lot more than the diver needs. Perhaps they are doubles wings being ill-advisedly used with single tank?

Here's some pictures of a properly sized wing:

Hard to tell in this pic, but look at the cam band buckles which I keep right up against the wing/plate on my right side. (Anyone with H cam bands knows this is necessary on an AL80) Accordingly, the fact that you can see the ENTIRE buckle on both the top and bottom bands would seem to indicate zero excess wing...

In this pic you can clearly see the entirety of the tank. Again, no excess wing-age to have any problem with.

The wing seen in the two pics above is a 40lb Oxycheq Mach V. It extends about 1" past the plate. Couldn't make it taco if I tried. Are there some people that dive with the wrong wing? Sure. Is there a proper wing for any/every dive. Yup. Is there a proper "jacket BCD" for every dive. Nope. Not even close.

 

[Sas]

That wing seems to be a lot more than the diver needs. Perhaps they are doubles wings being ill-advisedly used with single tank?

My wing is 32lb and is a single tank wing. If it has a bit of air in it, it wraps around the tank as have all single wings I have tried (OMS, Halycon, DSS, Zeagle, and a couple of others). I have not found this to be a problem.

 

[RJP]

My wing is 32lb and is a single tank wing. If it has a bit of air in it, it wraps around the tank as have all single wings I have tried...

Y'oughta try one of these...